The MetLife Building in Midtown is getting an energy-efficient, LED-powered sign to replace its iconic marker, whose 18-foot-tall letters have long glowed with 10,000 linear feet of energy-hogging …

Work also just began on the east façade of the 3.1 million-square-foot behemoth to replace Metlife’s former snowflake logo that’s made of four “M”s with its new, green-and-blue, single “M.” Later this summer, the logo on the west facade also will be replaced.